Termite-proofing agent and its application method

ABSTRACT

The present invention is a composition comprising a neonicotinoid-based compound having a high degree of insecticide activity, an organic solvent and a surfactant. The present invention is also a method that allows the obtaining of lumber that does not require termite-proofing treatment following production of lumber by injecting this composition into a tree trunk and allowing the chemical to circulate and disperse within the tree trunk.

This application is a 371 of International Application No.PCT/JP2005/004717 filed Mar. 10, 2005, which claims priority to JP2004-066675 filed Mar. 10, 2004, the contents of which are incorporatedherein by reference.

TECHNICAL FIELD

The present invention is a tree trunk injection preparation and a methodfor producing lumber that does not require termite-proofing treatmentfollowing lumber production by applying the tree trunk injectionpreparation.

More than twenty species of termites such as Japanese termites andOriental termites thrive in Japan, and their resulting damage to woodenstructures is so extensive that it is referred to as “flame-less fire”.Since lumber is used in the traditional Japanese construction method ofwooden framework construction and the conventional construction methodemployed in North America of framed wall construction in particular,once such structures become damaged by termites, the resulting damagecan be to the extent to which the structure must be rebuilt. Even in thecase of using a steel frame or reinforced concrete for the structuralmaterials, since wood is frequently used for the inner walls andinterior, there are many reports of termite damage in these cases aswell.

In the Kyushu, Shikoku, Chugoku, Kansai and Tokai regions where Orientaltermites thrive, the dissemination of insecticide into the soil and thespraying of insecticide onto wooden structural sections one meter orless above ground are essential for preventing termites during theconstruction of wooden structures. In addition, preventive treatment forsoil under the floors and wooden sections must be repeated by sprayingwith chemicals every three to five years.

Termite damage frequently occurs at locations out of view, such aswithin structural materials, beneath floors and inside walls, and thework involved to exterminate termites in these locations is frequentlydifficult.

Although various methods of chemical treatment are employed for the woodused in order to protect a structure from termite damage, each of thesetreatment methods has its own advantages and disadvantages, such as thework efficiency of chemical treatment, limitations due to the physicalproperties of the chemicals, and problems with toxicity for the workersand the environment.

BACKGROUND ART

Examples of methods that have been employed in the prior art forrot-proofing and termite-proofing structural wooden materials include(1) injection into the trunks of standing trees, (2) chemical treatmentof the cut ends of felled timber, (3) coating and spraying lumber withchemicals, (4) immersing lumber in chemicals, and (5) injectingchemicals into lumber under pressure.

The method involving injection into the trunks of standing trees is aneasy method, but it has poor treatment efficiency since considerabletime is required to inject a large amount of chemical in treatingindividual trees, and the chemical used must be soluble in water. Thus,this method is hardly used at all at present.

Height difference injection methods are typically used for treating thecut ends of felled timber with chemicals. Examples of such methodsinclude the Bushley method, in which the cross-sectional surfaces of thebases of bark-covered logs are coupled with a chemical tank installed ata high location immediately after felling followed by the injection ofchemical utilizing the water pressure resulting from this heightdifference, and a method in which, after peeling the bark for a distanceof about 10 cm from the base of bark-covered logs, the peeled base iscovered with one end of a tire tube and fastened to the log with wire ora rubber band, after which chemical is injected into the tube from theother end and the base of the log is inclined at a steep angle andallowed to stand undisturbed. These methods are also hardly used for thesame reasons as the aforementioned method involving injection into thetrunks of standing trees.

Methods involving coating or spraying lumber with chemicals are the mostcommon methods of rot-proofing and termite-proofing treatment, and areroutinely employed at building construction sites. In these methods, anemulsion or wettable powder containing rot-proofing and termite-proofingingredients is diluted with water, a chemical in which thetermite-proofing ingredient is diluted with kerosene is applied to thelumber with a brush, or the chemical is sprayed onto the lumber with asprayer. However, these methods have the shortcomings of requiringconsiderable time and trouble for treatment, the surfaces to which thechemical adheres are extremely limited to unevenness of coating orspraying, and the chemical being unable to be adequately impregnatedinto the lumber, thereby making lumber susceptible to infiltration byputrefying microorganisms and termite from those sections where thechemical has not adhered or only adhered in a small amount. In addition,there is also the problem of environmental contamination since thechemical sprays onto lumber other than the lumber targeted for spraying.

Although the method involving immersing lumber in a chemical allows thechemical to be more reliably impregnated into the lumber than theaforementioned coating or spraying, it has the shortcomings of requiringthe providing of a large immersion tank and a large volume of chemicalso that the lumber to be treated can be completely immersed.

Although methods involving the injection of a chemical into lumber underpressure enable chemicals to reliably penetrate inside the lumber in ashort period of time, they also have the shortcomings of requiring adevice to generate pressure, requiring a large amount of chemical in thesame manner as immersion methods, and require measures for preventingpollution with respect to treating the waste chemical followingtreatment. Although CCA (chromium-copper-arsenic) compounds having bothtermite-proofing and rot-proofing effects have been used as chemicals inthese methods, treatment using this method is decreasing rapidly for thereasons mentioned above.

As has been previously described, although there are numerous methodsfor termite-proofing treatment of lumber, since each of these methodshave problems, treatment is performed by selecting the method thought tobe optimum based on the respective situation. Among these, althoughinjection into the trunks of standing trees provides a simple methodthat is easy to implement, since it requires the injection of a largeamount of chemical and considerable time is required for that injection,it is currently hardly employed at all for reasons of poor treatmentefficiency. However, it is thought that this method would proliferateconsiderably if an active ingredient or preparation were available thatwould enable treatment to be performed with a small amount of chemicaland in a short period of time.

DISCLOSURE OF INVENTION

Neonicotinoid-based compounds are compounds that have a high degree oftermite insecticide action, have low toxicity with respect to people andexhibit very little dissipation in air, and several of these compoundsare used practically as termite control chemicals. However, sinceneonicotinoid-based compounds are essentially insoluble in water or onlya very small amount dissolves in water, they are nearly always used inthe form of a wettable powder. Lumber treated with a termite-proofingagent can be obtained as a result of allowing easy injection into treetrunks and circulating within the tree body by combining aneonicotinoid-based insecticide component with a solvent miscible inwater and a surfactant.

BASE MODE FOR CARRYING OUT THE INVENTION

The present invention relates to a tree trunk injection preparationcomprising (1) a neonicotinoid-based insecticide component that isvirtually insoluble in water or only a very small amount of whichdissolves in water, (2) a solvent miscible in water, and (3) asurfactant, and to a method for obtaining lumber that does not requiretermite-proofing treatment following lumber production by injecting saidtree trunk injection preparation into the trunk of a tree such as pine,cedar or cypress and circulating inside the tree body.

Although compounds such as nitenpyram, imidacloprid and thiacloprid arealso effective as neonicotinoid-based insecticide components in additionto those indicated in claim 1, organic phosphorus-based insecticidessuch as acephate, fenitrothion, ethylthiometon and diazinon, syntheticpyrethroid-based insecticides such as permethrin, etofenprox andsilafluofen, and carbamate-based insecticides such as oxamyl, methomyland benfuracarb are also effective.

In addition, disinfectants for rot-proofing may also be used alone ormixed with the aforementioned insecticides.

The solvent used in the composition of the present invention ispreferably that which is easily miscible with water, examples of whichinclude lower alcohols such as methanol and ethanol, ethers such asdioxane and tetrahydrofuran, ketones such as methyl ethyl ketone andcyclohexanone, esters such as ethyl acetate and butyl acetate,sulfoxides such as dimethylsulfoxide, nitriles such as acetonitrile,pyrrolidones such as N-methylpyrrolidone and N-ethylpyrrolidone, amidessuch as N,N-dimethylformamide, and glycols such as ethylene glycol,propylene glycol and diethylene glycol, their esters and their ethers.

Examples of surfactants used in the composition of the present inventioninclude anionic surfactants such as alkyl sulfate esters, alkanesulfonates, alkyl benzene sulfonates, alkyl phosphate esters, N-acylsarcosine salts, N-acyl alanine salts and succinates, cationicsurfactants such as alkyl amines, alkyl trimethyl ammonium salts,dialkyl dimethyl ammonium salts, alkyl dimethyl benzyl ammonium saltsand alkyl pyridinium salts, and nonionic surfactants such aspolyoxyethylene castor oils, polyoxyethylene hardened castor oils,polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers,polyoxyethylene alkyl phenyl ether formaldehyde condensation products,polyoxyethylene allyl phenyl ethers, polyoxyethylene allyl phenyl etherformaldehyde condensation products, polyoxyethylene glycol fatty acidesters, polyoxyalkylene alkyl ethers, sorbitan fatty acid esters,polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitolfatty acid esters, polyglycerin fatty acid esters, sucrose fatty acidesters and propylene glycol mono fatty acid esters.

Among these, a suitable nonionic surfactant is normally used alone or asa mixture with anionic surfactant. Preferable examples of nonionicsurfactants include polyoxyethylene hardened castor oils,polyoxyethylene alkyl ethers, polyoxyalkylene alkyl ethers,polyoxyethylene allyl phenyl ethers and polyoxyethylene sorbitan fattyacid esters.

Since the composition cannot be injected into a tree body if itsviscosity is excessively high, normally it is preferable to use solventand surfactant having low viscosity.

Although the amount of each component of the composition of the presentinvention can be suitably changed, active ingredient can be contained atabout 0.1 to 20% by weight and preferably about 1 to 10% by weight,solvent can be contained at about 30 to 90% by weight and preferablyabout 40 to 70% by weight, and surfactant can be contained at about 0 to20% by weight and preferably about 0 to 10% by weight.

The composition of the present invention is prepared by uniformlydissolving each component. The preparation method involves mixing anddissolving the total amount of components using a stirrer in a suitablylarge tank.

The method for applying the present composition to trees consists ofdrilling a hole in the trunk with a drill and so forth at a locationlower than the site where the tree is felled, and injecting thecomposition of the present invention contained in a suitable containereither without applying pressure or under pressure. Although the amountapplied varies according to the content of active ingredient and thetimber volume of the tree, in the case of a preparation having an activeingredient content of 3 to 5%, the applied amount is 100 to 1000 ml, andpreferably 200 to 600 ml, per cubic meter of timber volume. In addition,it is preferable to inject the preparation into the tree trunk using atleast two locations, and preferably 2 to 5 locations, so that thepreparation is uniformly dispersed within the tree trunk.

A further embodiment of the present invention is a method for obtaininga lumber product, comprising the steps of:

preparing a liquid mixture;

injecting said liquid mixture into a living tree;

thereafter felling said living tree and allowing it to air dry for threemonths; and

subsequently, processing said felled tree into said lumber product;

wherein said liquid mixture comprises a neonicotinoid-based insecticidecomponent selected from the group consisting of thiamethoxam,acetamiprid, dinotefuran and clothianidin, said neonicotinoid-basedinsecticide component being virtually insoluble in water or only a verysmall of which dissolves in water, at least one solvent miscible inwater, and

at least one surfactant, and

further wherein the processing of said felled tree into said lumberproduct does not include a termite-proofing treatment.

EXAMPLES

The following provides a detailed explanation of the contents of thepresent invention through examples, but the present invention is notlimited to these examples.

Example 1 Formulation of Injection Preparation

Formulation examples of an injection preparation having aneonicotinoid-based compound in the form of thiamethoxam as their activeingredient are shown in Table 1.

TABLE 1 Injection Preparation Formulations Formula No. 1 2 3 4 5 6 7 8 910 Thiamethoxam bulk 4.0 4.0 4.0 4.0 4.0 4.0 4.0 4.0 4.0 4.0 drugCyclohexanol 30.0 Diethylene glycol 30.0 Cyclohexanone 30.0 20.0 20.020.0 20.0 20.0 N-methylpyrrolidone 30.0 N,N- 30.0 dimethylformamideAcetone 20.0 20.0 20.0 20.0 20.0 20.0 20.0 20.0 20.0 20.0 Methanol 31.031.0 31.0 31.0 41.0 41.0 41.0 41.0 41.0 31.0 Water 5.0 5.0 5.0 5.0 5.05.0 5.0 5.0 5.0 5.0 NK1001) 10.0 10.0 10.0 10.0 NK1352) 10.0 7.0 7.010.0 NK13723) 10.0 NK15484) 10.0 NK41C5) 3.0 NK41B6) 3.0 Total 100.0100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 Notes:1)Polyoxyethylene hardened castor oil 2)Polyoxyethylene styryl phenylether 3)Polyoxyethylene nonyl phenyl ether 4)Polyoxyethylene oleyl ether5)Calcium alkyl benzene sulfonate 6)Sodium alkyl benzene sulfonate

Although any of the preparations shown in Table 1 can be used, thosewhich do not cloud or precipitate when diluted in water, and have apreparation viscosity (Type B viscometer) that allows them to beinjected rapidly are preferable.

Example 2 Injection into Tree

The preparation of Formula No. 9 among the formulas shown in Example 1was injected into the trunks of 20-40 year old pine trees at a location30 cm above the ground at 200, 400 and 600 ml per cubic meter of timbervolume. Injections were made without applying pressure and underpressure, and the preparation was injected into three trees for eachinjection volume.

In addition, the preparation was injected into trunks of about 30 yearold cedar trees in the same manner as the pine trees.

TABLE 2 Injection of Preparation into Standing Pine Trees Trunk diameterof tree Trunk at the Number of Injection height of Height TimberInjection hole(s) on Time for per cubic chest of tree volume volumeinjection Injection injection meter (cm) (m) (m3) (ml) container method(min) 200 ml 18 12 0.16 32 1 Without 45 applying pressure 22 14 0.26 522 Without 30 applying pressure 25 18 0.4 80 2 Without 45 applyingpressure 20 12 0.19 38 1 Under 15 pressure 25 15 0.3 60 2 Under 12pressure 25 18 0.4 80 2 Under 20 pressure 400 ml 20 13 0.2 80 2 Without55 applying pressure 22 16 0.29 116 2 Without 70 applying pressure 28 200.54 216 3 Without 70 applying pressure 18 13 0.17 68 2 Under 15pressure 20 15 0.23 92 2 Under 25 pressure 24 18 0.39 156 3 Under 40pressure 600 ml 20 12 0.19 114 2 Without 70 applying pressure 25 15 0.3180 3 Without 60 applying pressure 29 20 0.58 348 5 Without 90 applyingpressure 19 11 0.16 96 2 Under 25 pressure 23 13 0.26 156 3 Under 25pressure 27 15 0.39 234 4 Under 40 pressure

Preparations were injected at equal volumes into each hole.

Preparations were pressurized with gas by placing the preparations in aspecial-purpose pressurizing container.

TABLE 3 Injection of Preparation into Standing Cedar Trees Trunkdiameter of tree Number of Trunk at the Height hole(s) Injection heightof Timber Injection on Time for per cubic of chest tree volume volumeinjection Injection injection meter (cm) (m) (m³) (ml) container method(min) 200 ml 19 14 0.2 40 2 Without 25 applying pressure 20 15 0.23 46 2Without 33 applying pressure 20 15 0.23 46 2 Without 35 applyingpressure 20 14 0.22 44 2 Under 12 pressure 20 15 0.23 46 2 Under 15pressure 22 15 0.28 56 2 Under 18 pressure 400 ml 20 14 0.22 88 2Without 50 applying pressure 20 14 0.22 88 2 Without 55 applyingpressure 22 15 0.28 112 2 Without 65 applying pressure 20 14 0.22 88 2Under 25 pressure 20 14 0.22 88 2 Under 25 pressure 21 15 0.25 100 2Under 30 pressure 600 ml 20 14 0.22 132 2 Without 75 applying pressure20 14 0.22 132 2 Without 80 applying pressure 22 15 0.28 168 3 Without60 applying pressure 20 14 0.22 132 2 Under 35 pressure 22 14 0.26 156 3Under 30 pressure 22 15 0.28 168 3 Under 35 pressure

Preparations were injected at equal volumes into each hole.

Preparations were pressurized with gas by placing the preparations in aspecial-purpose pressurizing container.

As is shown in Tables 2 and 3, 200 to 600 ml per cubic meter of thepreparations were able to be smoothly injected into both the pine treesand cedar trees.

In the case of the pine trees, the preparations were able to be injectedin 30 to 90 minutes without applying pressure and in 12 to 40 minutesunder pressure. In the case of the cedar trees, the preparations wereable to be injected in 25 to 80 minutes without applying pressure and in12 to 35 minutes under pressure.

Example 3 Termite-Proofing Effects on Wood Treated by Trunk Injection

The pine and cedar trees treated in Example 2 were left standing for 3months after injection of chemical to allow the chemical to dispersethroughout the tree trunk. Three months later, one test tree wasappropriately selected from each test area, and cut down at a location50 cm above the ground. The wood was allowed to air dry for 3 months inthe shade, and discs having a thickness of 2 cm were cut starting fromthe base of the dried wood at 1 m intervals to a length of 4 m followedby obtaining wood blocks measuring 2 cm×2 cm×2 cm from these discs.Sterilized and disinfected sand containing a suitable amount of moisturewas placed in the bottom of a glass container having a diameter of 13 cmand height of 3 cm, and the wood blocks were then placed on top of thesand. Ninety worker Oriental termites and 10 soldier Oriental termiteswere placed in the glass containers containing the wood blocks, and thenraised for 4 weeks in a constant temperature thermostat at a temperatureof 25 degrees followed by investigating the viability of the termitesand the degree of damage to the wood blocks (weight reduction).

Those results are shown in Tables 4 and 5.

TABLE 4 Termite-Proofing Effects on Pine Wood Treated by Trunk InjectionSampling site Trunk 1 m 2 m 3 m 4 m Injection Number Number NumberNumber per cubic Injection of Weight of live Weight of live Weight oflive Weight meter method termites reduction termites reduction termitesreduction termites reduction 200 ml Without 0 0.2 0 0 0 0 0 0 applyingpressure Under 0 0 0 0.1 0 0 0 0 pressure 400 ml Without 0 0 0 0 0 0 0 0applying pressure Under 0 0.1 0 0 0 0 0 0 pressure 600 ml Without 0 0 00 0 0 0 0 applying pressure Under 0 0 0 0 0 0 0 0 pressure Control 91224 96 291 92 243 90 240

Number of live termites is expressed as the number of termites, whileweight reduction is expressed in mg.

The average values are shown obtained by repeating testing three timesin each area.

An untreated pine wood block was used as the control.

TABLE 5 Termite-Proofing Effects on Cedar Wood Treated b Trunk InjectionSampling site Trunk 1 m 2 m 3 m 4 m Injection Number Number NumberNumber per cubic Injection of live Weight of live Weight of live Weightof live Weight meter method termites reduction termites reductiontermites reduction termites reduction 200 ml 0 0 0 0 0 0 0 0 0 0.1 0 0.10 0 0 0 400 ml 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 600 ml 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 Control 88 176 86 153 91 201 88 177

Number of live termites is expressed as the number of termites, whileweight reduction is expressed in mg.

The average values are shown obtained by repeating testing three timesin each area.

An untreated cedar wood block was used as the control.

As is shown in Tables 4 and 5, none of the Oriental termites survivedand there was hardly weight reduction observed in the wood blocks due totermite damage in both pine and cedar wood blocks chemically treated atany of the injection volumes and injection methods.

INDUSTRIAL APPLICABILITY

Instead of treating lumber with a termite-proofing agent by a methodsuch as coating or spraying at the construction site as in the priorart, the present invention allows the obtaining of lumber having a highdegree of resistance to termite damage that is not required to betreated with termite-proofing agent at the construction site byinjecting a neonicotinoid-based insecticide component into the trunks ofstanding trees in advance.

As a result of using lumber treated by the present invention, there isno environmental contamination by chemicals since it is not necessary totreat the lumber by coating or spraying a termite-proofing agent at theconstruction site. In addition, since chemical is dispersed inside thelumber, the effects can be expected to be demonstrated for a long periodof time.

The invention claimed is:
 1. A method for obtaining a lumber product,comprising the steps of: preparing a liquid mixture; injecting saidliquid mixture into a living tree; thereafter felling said living treeand allowing it to air dry for three months; and subsequently,processing said felled tree into said lumber product, wherein saidliquid mixture comprises a neonicotinoid-based insecticide componentselected from the group consisting of thiamethoxam, acetamiprid,dinotefuran and clothianidin, said neonicotinoid-based insecticidecomponent being virtually insoluble in water or only a very small amountof which dissolves in water, at least one solvent miscible in water, andat least one surfactant, and further wherein the processing of saidfelled tree into said lumber product does not include a termite-proofingtreatment.
 2. The method of claim 1, further comprising waiting at leastthree months between said injecting step and said felling step.
 3. Themethod of claim 1, wherein the insecticide is thiamethoxam.
 4. Themethod of claim 1, wherein the at least one solvent is selected from thegroup consisting of lower alcohols, glycols and their derivatives,ethers, ketones, esters, sulfoxides, nitrites, pyrrolidones, glycerinsand amides.
 5. The method of claim 1, wherein the at least onesurfactant is selected from the group consisting of polyoxyalkylenehardened caster oils, polyoxyethylene alkyl ethers, polyoxyethylenepolyoxypropylene alkyl ethers, polyoxyethylene sorbitan fatty acidesters, polyoxyethylene sorbitol fatty acid esters, polyglycerin fattyacid esters, sucrose fatty acid esters, polyoxyalkylene (poly)styrenephenols, and polyoxyalkylene(poly)styrene cresols and their sulphateesters and phosphate esters and their salts.
 6. The method of claim 1,wherein the neonicotinoid-based insecticide component is present from0.1 to 20 wt %, the at least one solvent is present from 30 to 90 wt %,and the at least one surfactant is present less than 20 wt %, whereinsaid wt % is based on the weight of the liquid mixture.
 7. The method ofclaim 1, wherein the neonicotinoid-based insecticide component ispresent from 1.0 to 10 wt %, the at least one solvent is present from 40to 70 wt %, and the at least one surfactant is present less than 10 wt%, wherein said wt % is based on the weight of the liquid mixture.